-/* called with local bh disabled */
-static int __dccp_v4_check_established(struct sock *sk, const __u16 lport,
- struct inet_timewait_sock **twp)
-{
- struct inet_sock *inet = inet_sk(sk);
- const u32 daddr = inet->rcv_saddr;
- const u32 saddr = inet->daddr;
- const int dif = sk->sk_bound_dev_if;
- INET_ADDR_COOKIE(acookie, saddr, daddr)
- const __u32 ports = INET_COMBINED_PORTS(inet->dport, lport);
- unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport);
- struct inet_ehash_bucket *head = inet_ehash_bucket(&dccp_hashinfo, hash);
- const struct sock *sk2;
- const struct hlist_node *node;
- struct inet_timewait_sock *tw;
-
- prefetch(head->chain.first);
- write_lock(&head->lock);
-
- /* Check TIME-WAIT sockets first. */
- sk_for_each(sk2, node, &(head + dccp_hashinfo.ehash_size)->chain) {
- tw = inet_twsk(sk2);
-
- if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
- goto not_unique;
- }
- tw = NULL;
-
- /* And established part... */
- sk_for_each(sk2, node, &head->chain) {
- if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
- goto not_unique;
- }
-
- /* Must record num and sport now. Otherwise we will see
- * in hash table socket with a funny identity. */
- inet->num = lport;
- inet->sport = htons(lport);
- sk->sk_hash = hash;
- BUG_TRAP(sk_unhashed(sk));
- __sk_add_node(sk, &head->chain);
- sock_prot_inc_use(sk->sk_prot);
- write_unlock(&head->lock);
-
- if (twp != NULL) {
- *twp = tw;
- NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
- } else if (tw != NULL) {
- /* Silly. Should hash-dance instead... */
- inet_twsk_deschedule(tw, &dccp_death_row);
- NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
-
- inet_twsk_put(tw);
- }
-
- return 0;
-
-not_unique:
- write_unlock(&head->lock);
- return -EADDRNOTAVAIL;
-}
-
-/*
- * Bind a port for a connect operation and hash it.
- */
-static int dccp_v4_hash_connect(struct sock *sk)
-{
- const unsigned short snum = inet_sk(sk)->num;
- struct inet_bind_hashbucket *head;
- struct inet_bind_bucket *tb;
- int ret;
-
- if (snum == 0) {
- int low = sysctl_local_port_range[0];
- int high = sysctl_local_port_range[1];
- int remaining = (high - low) + 1;
- int rover = net_random() % (high - low) + low;
- struct hlist_node *node;
- struct inet_timewait_sock *tw = NULL;
-
- local_bh_disable();
- do {
- head = &dccp_hashinfo.bhash[inet_bhashfn(rover,
- dccp_hashinfo.bhash_size)];
- spin_lock(&head->lock);
-
- /* Does not bother with rcv_saddr checks,
- * because the established check is already
- * unique enough.
- */
- inet_bind_bucket_for_each(tb, node, &head->chain) {
- if (tb->port == rover) {
- BUG_TRAP(!hlist_empty(&tb->owners));
- if (tb->fastreuse >= 0)
- goto next_port;
- if (!__dccp_v4_check_established(sk,
- rover,
- &tw))
- goto ok;
- goto next_port;
- }
- }
-
- tb = inet_bind_bucket_create(dccp_hashinfo.bind_bucket_cachep,
- head, rover);
- if (tb == NULL) {
- spin_unlock(&head->lock);
- break;
- }
- tb->fastreuse = -1;
- goto ok;
-
- next_port:
- spin_unlock(&head->lock);
- if (++rover > high)
- rover = low;
- } while (--remaining > 0);
-
- local_bh_enable();
-
- return -EADDRNOTAVAIL;
-
-ok:
- /* All locks still held and bhs disabled */
- inet_bind_hash(sk, tb, rover);
- if (sk_unhashed(sk)) {
- inet_sk(sk)->sport = htons(rover);
- __inet_hash(&dccp_hashinfo, sk, 0);
- }
- spin_unlock(&head->lock);
-
- if (tw != NULL) {
- inet_twsk_deschedule(tw, &dccp_death_row);
- inet_twsk_put(tw);
- }
-
- ret = 0;
- goto out;
- }
-
- head = &dccp_hashinfo.bhash[inet_bhashfn(snum,
- dccp_hashinfo.bhash_size)];
- tb = inet_csk(sk)->icsk_bind_hash;
- spin_lock_bh(&head->lock);
- if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) {
- __inet_hash(&dccp_hashinfo, sk, 0);
- spin_unlock_bh(&head->lock);
- return 0;
- } else {
- spin_unlock(&head->lock);
- /* No definite answer... Walk to established hash table */
- ret = __dccp_v4_check_established(sk, snum, NULL);
-out:
- local_bh_enable();
- return ret;
- }
-}